This proposal for the Physician Scientist Award is designed to provide the candidate with rigorous training in cell and molecular biology to apply to the study of retinal development and optic nerve regeneration. This will be achieved in Phase 1 through a combination of didactic course work, including a tutorial in molecular biology under the preceptorship of Dr. Brian Seed, and a program of experimental work in cell biology, in the laboratory of Dr. Linda Chun at the Massachusetts General Hospital. A strong theoretical framework will be acquired in course work in molecular, cellular, and developmental biology at Harvard University and attendance at research seminars at Harvard and MGH. The experimental work will involve learning techniques of cell purification developed in Dr. Chun's laboratory, as well as cell culture, immuno- histochemistry, in situ hybridization and production of monoclonal antibodies to retinal cell surface antigens. Specific experiments in Phase 1 will be undertaken to (l) purify and culture retinal subtypes (ganglion cells (RGCs), amacrine cells, GABAergic neurons) by means of antibody mediated adhesion, and (2) determine the role of various trophic factors (BDNF, NGF, the FGFs, and a new, partially characterized survival promoting activity for postnatal RGCs, currently under investigation in Dr. Chun's laboratory? in promoting the survival and process outgrowth of these purified subtypes in culture and in vivo. Phase II work will be directed toward an integration of the knowledge gained from these in vitro assays into the experimental animal, with factors assayed for their survival and neurite outgrowth promoting ability after optic nerve injury. An attempt will therefore be made to progress over the course of the project term from a basic understanding of the activity of these factors on a cellular level, to their potential therapeutic effects after optic nerve and retinal trauma.